Prep for txData decoder tests

1 files changed, 24 insertions, 1 deletions

diff --git a/packages/utils/src/address_utils.ts b/packages/utils/src/address_utils.ts
index 1fc960408..318504c37 100644
--- a/packages/utils/src/address_utils.ts
+++ b/packages/utils/src/address_utils.ts
@@ -1,10 +1,13 @@
-import { addHexPrefix, stripHexPrefix } from 'ethereumjs-util';
+import { addHexPrefix, stripHexPrefix, sha3 } from 'ethereumjs-util';
 import * as jsSHA3 from 'js-sha3';
 import * as _ from 'lodash';
 
+import { BigNumber } from './configured_bignumber';
+
 const BASIC_ADDRESS_REGEX = /^(0x)?[0-9a-f]{40}$/i;
 const SAME_CASE_ADDRESS_REGEX = /^(0x)?([0-9a-f]{40}|[0-9A-F]{40})$/;
 const ADDRESS_LENGTH = 40;
+const MAX_DIGITS_IN_UNSIGNED_256_INT = 78;
 
 export const addressUtils = {
     isChecksumAddress(address: string): boolean {
@@ -43,4 +46,24 @@ export const addressUtils = {
     padZeros(address: string): string {
         return addHexPrefix(_.padStart(stripHexPrefix(address), ADDRESS_LENGTH, '0'));
     },
+    /**
+     * Generates a pseudo-random 256-bit salt.
+     * The salt can be included in a 0x order, ensuring that the order generates a unique orderHash
+     * and will not collide with other outstanding orders that are identical in all other parameters.
+     * @return  A pseudo-random 256-bit number that can be used as a salt.
+     */
+    generatePseudoRandomSalt(): BigNumber {
+        // BigNumber.random returns a pseudo-random number between 0 & 1 with a passed in number of decimal places.
+        // Source: https://mikemcl.github.io/bignumber.js/#random
+        const randomNumber = BigNumber.random(MAX_DIGITS_IN_UNSIGNED_256_INT);
+        const factor = new BigNumber(10).pow(MAX_DIGITS_IN_UNSIGNED_256_INT - 1);
+        const salt = randomNumber.times(factor);
+        return salt;
+    },
+    generatePseudoRandomAddress(): string {
+        const randomBigNum = addressUtils.generatePseudoRandomSalt();
+        const randomBuff = sha3(randomBigNum.toString());
+        const randomAddress = `0x${randomBuff.slice(0, 20).toString('hex')}`;
+        return randomAddress;
+    }
 };